Feed assemblies for textile carding machines have been heretofore utilized to perform the general function of feeding fibers of various length to an opening roll commonly referred to as a licker-in and at the same time maintain control of unopened tufts and lumps to prevent plucking and jerk-ins. The assemblies typically have included a feed plate or table terminating in a concave trough adjacent the lickerin in which a feed roll is supported. A gap is defined between the feed roll and feed plate between which the fibers are fed. This type feed assembly is used for carding cotton and synthetic fibers up to and including 21/2 inches in length, but cannot be used with any degree of satisfaction when carding long staple synthetic fibers due to excessive breakage. Regard-applied. Two type feed rolls are utilized for this type of assembly both of which serve the same purpose, namely fluted and spirally wound serrated metallic wire.
Another prior feed assembly consists of two metallic wire wound feed rolls and a feed roll clearer and is used when carding long staple synthetic fibers. The fiber is fed to lickerin by the feed rolls and the clearer is there to prevent fibers wrapping around the feed rolls. This type is reasonably effective in preventing jerk-ins, but is ineffective in providing a good combing action due to lack of control of fibers.
However, in the event a heavy mass of fibers is concentrated in the form of a lump in a small area of the lap, the two prior feed assemblies heretofore described will allow jerk-in of irregular fiber masses. This is due to the deflections of feed roll and feed plate as the lump passes therebetween which results in loss of control over the fibers since they are no longer held tightly between the feed roll and plate and can be jerked in by the licker-in. In an attempt to exert and maintain control extreme pressures have been used between the feed roll and feed plate. However, if the fibers are held too tightly, they are broken when grabbed at by the licker-in. All of which adversely affects the quality of the fiber web being carded and can result in damage to the various rolls and clothing on the carding machine.
A feed device has been proposed in U.S. Pat. No. 4,222,154 wherein a uniform fiber thickness delivered between the feed roll and feed plate is provided by a presser plate 20 which compresses the fibers prior to feeding by the feed assembly. However, lump fiber masses can still be released between the feed roll and plate after compression still posing the problem of jerk-ins because of loss of fiber control.
Accordingly, an important object of the present invention is to provide a feed assembly and method for a carding machine which improves the quality of the web being carded by the elimination of fiber jerk-ins or plucking as a result of better fiber control and combing action.
Still another important object of the present invention is to provide feed assembly for a carding machine which increases the quality of the web being carded by providing better separation of cotton fibers and undesirable impurities.
Still another important object of the present invention is to provide a feed assembly for a carding machine which improves the efficiency of the carding machine by reducing the number of carding machine stops by eliminating fiber jerk-ins.
Still another important object of the present invention is to provide a feed assembly for a carding machine which is versatile and can be used for long and short staple fibers without an increase in fiber breakage and may be adapted to picker lap or chute feed systems.
Still another important object of the present invention is to provide a feed assembly for a carding machine which reduces maintenance costs by eliminating fiber jerk-ins and resulting clothing damage to licker-in, main cylinder, carding flats, and doffer roll.